# Variables & expressions introduction

Contents

Learn what variables are and practice using them in expressions. The major concepts covered in these tutorials are substitution, the distributive property, and combining like terms.

## Intro to variables

Wait, why are we using letters in math? How can an 'x' represent a number? What number is it? This tutorial is great if you're just beginning to delve into the world of variables and expressions.

## Expression value intuition

Explore how the value of an algebraic expression changes as the value of its variable changes.

## Substitution & evaluating expressions

Learn how to substitute (or "plug in") values for variables and evaluate algebraic expressions.

## Evaluating expressions word problems

Learn how to plug in values to evaluate real-world expressions.

## Writing algebraic expressions introduction

Learn the basics of writing expressions with variables.

## Writing basic algebraic expressions word problems

Learn how to write algebraic expressions (expressions with variables) to model real-world situations.

## Evaluating expressions (articles only)

Covers the content in "Introduction to variables", "Expression value intuition", "Substituting and evaluating expressions", and "Evaluating expressions word problems" with only articles.

## Evaluating expressions (fast track)

Covers the content in "Introduction to variables", "Expression value intuition", "Substituting and evaluating expressions", and "Evaluating expressions word problems" more efficiently for advanced learners

## Writing expressions (fast track)

Covers the content in "Writing algebraic expressions introduction" and "Writing basic algebraic expressions word problems" more efficiently for advanced learners